328248-72-2Relevant academic research and scientific papers
1,4-didehydronaphthalene
Roth, Wolfgang R.,Hopf, Henning,Wasser, Thorsten,Zimmermann, Heiko,Werner, Christian
, p. 1691 - 1695 (1996)
The energy profile of the Bergman equilibrium o-diethinylbenzene (1) ? 1,4-didehydronaphthalene (2) has been established from the temperature and NO dependence of the trapping rate of the diradicals 2 which leads to a heat of formation for 2 of ΔHf0 = 152.9 ± 1.4 kcal·mol-1. Activation parameters for the hydrogen abstraction of 2 and 1,4-didehydrobenzene (5) have been derived from the rate of the naphthalene and benzene formation, when 1 and cis-3-hexene-1,5-diyne (4) are heated in the presence of methanol, toluene, and 1,4-cyclohexadiene. VCH Verlagsgesellschaft mbH, 1996.
The Energy Well of Diradicals, V. - 1,3,5-Cyclohexatriene-1,4-diyl and 2,4-Cyclohexadiene-1,4-diyl
Roth, Wolfgang R.,Hopf, Henning,Horn, Carina
, p. 1765 - 1780 (2007/10/02)
The energy profile of the Bergman rearrangement of (Z)-3-hexene-1,5-diyne (4) has been established from the NO and oxygen dependance of the trapping rate of the intermediate diradical 1 which leads to a heat of formation for 1,4-didehydrobenzene (1) of ΔH0f = 138.0 +/- 1.0 kcal * mol-1.By the same technique the heat of formation of 1,2,4-cyclohexatriene (2), generated by thermolysis of (Z)-1,3-hexadien-5-yne (10), gives ΔH0f = 105.1 +/- 1.0 kcal * mol-1 which indicates a high diradical character for 2. - Key Words: Diradicals / NO and O2 trapping / Heat of formation / Energy well / Rearrangements / Bergman cyclisation
